can I hire somebody here?

I don't need that, it is an 89 700r4, all that I need is one wire to lock the converter, it was just an after thought of what else i could use it for.
but I do have an agenda for this device, I'm not saying what it is, will you build it or not?

Nope. Sorry to many unknowns. Custom vehicle stuff is never simple plug and play. I know better.

can you point me to somebody that can?
but I think this is a cop out b/c you know all there is to know to make the device....

I or many others here could make a circuit that probably would work but not for $20! Realistically doing a custom circuit to match the tach input and desired functions would take most of a day to design and build and then do a test and tune with actual real signal inputs.
Although I am set up to build one it would still cost you around $20 for the parts plus $25 an hour for about 8 -10 hours.

Or more likely several of us would have talked you through a full build up that you did yourself for what ever the parts cost you. You would have got valuable help and learning experience and we all could have put our collective heads together and came up with a good design. We tend to do that fairly often.

But mostly its because you basically came off a bit too shady for my preferences.

Had you just came out directly and said what your attempting to do and why regardless of its moral, ethical, safety or lack of general common sense I would have helped. I am known to do that here.

Overall it was simply the avoiding explaining the real intention and application of the device I didn't like. Plus the number of things along the way just dont seem to add up for me.

The biggest being that I sort of have doubts that someone would have a nicer car like that with a hack job carburated engine attached to a semi electronic transmission installed in it. Unless they got it really cheap because of it which means it would most likely have many more problems with it as well. One that a $20 circuit wont fix I know that much.

Plus the circuit you want is in no way correct for any type of torque converter lock up system. The real factory ones used several inputs simultaneously from the throttle position, manifold vacuum, engine speed, engine temp, vehicle speed, gear selector, and brakes to control the torque converter lockup function. Rate of RPM change is not one of the parameters used.

well, to be honest, if I am wiling to pay, but if I could learn that would be better.... if you (or anybody else for that matter) are/is willing to help me.

and while I admit, I don't really what to say what my "secret" is I do have more than one use for it, of which I told you two of them.
But i did say that if I got some help I would say what it is being used for, exactly, but I am not just going to say up front. I can assure it it is moral and car related.

And I do kind of take offense at it being a "hack job". I do a lot of stuff as cheap as I can and I do as much work on my car as I can by myself. I have a very good mechanical knowledge of how things work. I am going to show you the "hack job" motor, which looks like a stock motor (this is good for racing b/c it does not scare people). Ok, well, by some standards what I'm doing is not completely ethical, I like racing. Plain and simple.
and I know all too well the dangers of it, but I really prefer not to go into it too much (although if you want to talk about it you can send em a PM and I will tell you).

ok, so here is my hack job motor, 100% GM except the intake. It is not pretty but when it warms up I will spend some time making it look nicer, it has been cold.



=============================================

I know it is not the best looking engine, but I do have a video of how it runs to show that I do know how to build a motor and tune it....
I really hope this let's you know I am for real here.... not that I have a lot of money, but that I allocate the time and have the patience to learn how stuff works and also have the ability to apply it.
YouTube - c4 Corvette burnout

like i said, I know cars, the mechanical side of things. I do not know electronics, and i need this specialty circuit, that in my head seems like it should be simple to build... but with only the most basic understanding of electronics I cannot do it by myself. Just like baking a cake is easy... IF you know how to cook.
I know you know how to cook up this device, and I offered to pay. $250 is more than I expected though.... but if it was something that would help me learn something new and was something that I could recreate if I ever needed something like it in the furture I would be willing to do that. I only have $53 right now to spare until my next pay check though.

I know all this sounds ridiculous but I am just asking for help to build my dream car. I could easily go to the salvage yard and scrounge up the parts to do what I wanted in a more conventional manner but somehow, to me anyways, that would kill some of the magic of it. I hope you can understand where i'm coming from and help me.... please.

ok i can help you a little bit but not for completion, just check the attched circuits,

the 1st one is a frequency to voltage convertor that has a range of 0-10kHz, and 0- (-10)V out put. you have to modify some components to achive correct scaling for 0-900 rpm. still you can try trial and error.
my advise is to use all 4 firing signals as a signal train to give frequency input then it will be 4 times, it will have some advantages.

2nd circuit is a differenciator and comparator, it will only respond to any change in frequency and give out put. the out put level is proportional to the rate of change of frequency. its gain can be adjusted by slection of R & C on the diagram, the preset will set your trip point.

some one can further help to you to simulate and give correct values. the rest you shoudl try your self

wow Mbarazeen, thanks for the help!
unfortunately I'm already stuck on the very first item

in the diagram the first item is a Schmitt 40106 trigger inverter.

I open yenka and that IS listed (wohoo!) .. but it only has one wire in and one wire out.
Then I search google and I find what looks like an integrated circuit with 12 wires?

so now i'm seeing the same IC with 3 different setups?

ok, looking around I find this:
Schmitt Trigger Applications

there it appears to be a device that has 5 wires, but the symbol only has 2, how can that be? This is very confusing stuff here ;p

mbarazeen said:

ok i can help you a little bit but not for completion, just check the attched circuits,

the 1st one is a frequency to voltage convertor that has a range of 0-10kHz, and 0- (-10)V out put. you have to modify some components to achive correct scaling for 0-900 rpm. still you can try trial and error.
my advise is to use all 4 firing signals as a signal train to give frequency input then it will be 4 times, it will have some advantages.

2nd circuit is a differenciator and comparator, it will only respond to any change in frequency and give out put. the out put level is proportional to the rate of change of frequency. its gain can be adjusted by slection of R & C on the diagram, the preset will set your trip point.

some one can further help to you to simulate and give correct values. the rest you shoudl try your self

Click to expand...

The differentiator will probably oscillate unless you add a small resistor (e.g., 100 ohms) in series with the capacitor.

ok, if anybody else is trying to do this and have yenka here is a negative voltage circuit i built from this site ( 555 Negative Voltage Generator ) in it to run the op-amp...
**broken link removed**

Nice small block Chevy. Do I spy a Nitrous oxide injector plate under the carburettor?

no nitrous, it is a spacer plate so I could run a Q-jet. i had a Holley double pumper on it but I have a goal of 20 MPG.... and short of EFI a Q-jet was the only way I thought I might be able to do it, with the right tuning it is easy to make power with a Q-jet

how about that 40106 schmitt trigger inverter in yenka, how do I wire it up??

Let me see if I have this right. You have a carburated engine that you want to shut-off the fuel supply to if it revs to quickly, to save the engine? Shutting-off the fuel supply won't do it! What about the fuel in the float bowls of the carb? The engine will continue to run until that is gone.

And your wrong about what a "rev-limiter" does. It doesn't shut down the ignition, it Retards the timing to lower the revolutions. Shutting-off the ignition would still allow the fuel/air mixture to flow into the exhaust system. Then when it reset it would ignite and cause a backfire in the muffler. The older guy's here might remember doing that as a kid, shut-off the key and turn it back on to cause a "bang" Only works with a stick shift.

A MSD or similar ignition Rev limiter is really what you need to do this. With out screwing up your car. If you want to learn some electronics and make something for the car, check out the threads on "Knight Rider Lights" !!!

I want to turn on an auxiliary fuel pump, unlock my converter and one other thing....
and a rev limiter does shut down the ignition. well new EFI cars shut down injectors, but old type MSD style kill the ignition.

Knight Rider lights... cool, but I want to build this, why is everybody telling me what I need? I know what I need, I just don't know how to make it.. :rollseyes:

is what I NEED is somebody to tell me what these "devices" are in the diagrams above.... I know what resistors are, capacitors, diodes, transistors... but anything beyond that is NEW to me...

joe_rocket said:

no nitrous, it is a spacer plate so I could run a Q-jet. i had a Holley double pumper on it but I have a goal of 20 MPG.... and short of EFI a Q-jet was the only way I thought I might be able to do it, with the right tuning it is easy to make power with a Q-jet

how about that 40106 schmitt trigger inverter in yenka, how do I wire it up??

Click to expand...

I just installed Yenka, so I know almost nothing about it. Keep this in mind when reading the rest of this post.
CD40106 is an IC containing 6 identical Schmitt triggers. The power supply pins are common to all of them. When you place a 40106 on a schematic in Yenka, the power supply pins are not shown, because Yenka only simulates the logic function. The circuit you are trying to simulate uses the 40106 in an unconventional fashion, where power supply currents are an essential part of the sim. There are other ways to simulate the 40106 function (using voltage-controlled switches), but I don't know how to do that in Yenka.

joe_rocket said:

ok, looking around I find this:
Schmitt Trigger Applications

there it appears to be a device that has 5 wires, but the symbol only has 2, how can that be? This is very confusing stuff here ;p

Click to expand...

here you want to use ground supply of the smith trigger with op-amp (OP-07) so i sugest you to 1st assemble the frequency to voltage converter. give some frequency input from a function generator or any other mean to scale it down to 0-9000 rpm.

your negetive voltage regulator would gwork fine i hope. for the time you do it with two batteries of 12V or etc.

the second part is the diffrenciator and comparator using operational amplifier (not a logic gate), you can use LM324. as you mentioned you have to give the input of the freq-voltage convertor to that and the final output you have to tune to your requirement.

rather than wasting your time on simulations you build and check with real situation, its not a big circuit for you to play around.

thanks for the help. so here is what I need to go to town and order?

frequency to voltage converter:

40106 schmitt trigger inverter x 1

Op-amp: OP-07 x 1 << is this the part number?

Capacitors:
5 nf x 1
0.1 uf x 1
1 uf x 1

Resistors:
3.3k x 1
10k variable x 1



negative voltage circuit:
resistors:
2k
10k

capacitors:
1 nf
470 uf x 2


IC:
NE555



Differentiator Circuit:

capacitors:
size unknown ? x1 << any idea of a starting size?

resistors:
size unknown x1 << any idea of a starting size?

100k x 1
100k variable x 1

ICs:
LM324 x2 << is this correct?

again, thanks for the help, esp Mbarazeen

now you are on the right direction, buy the ICs as you mentioned, OP-07 is the part number.
for capacitors and resistors, you can buy some different values since its not that expensive. if you will keep an old board of a radio or TV or a computor power supply you can find many caps and resistors if you need to have a try with different values.

LM 324 x1 is enough since it has two op-amps inside, check the datasheets for any reference from

http://search.datasheetcatalog.net/key/LM324

Ok, sounds great!
so the way this works...
the frequency to voltage does exactly what it says, it outputs a certain voltage for each frequency.
the differentiator circuit, according to this: detects a change in voltage and outputs that "change" which I can then run through a diode (or zener diode?) so it only outputs a positive or negative voltage, or even run two diodes and use it to control different things depending on if the engine is accelerating or decelerating

The right-hand side of the capacitor is held to a voltage of 0 volts, due to the "virtual ground" effect. Therefore, current "through" the capacitor is solely due to change in the input voltage. A steady input voltage won't cause a current through C, but a changing input voltage will.

Click to expand...

I'm liking this, it's new and fascinating to me
My only question now is why are there two LM324's being used in the differentiator circuit? I assume? that it is b/c it needs the variable resistor in that circuit to be able to adjust for different input voltages/time making it adjustable?

joe_rocket said:

My only question now is why are there two LM324's being used in the differentiator circuit? I assume? that it is b/c it needs the variable resistor in that circuit to be able to adjust for different input voltages/time making it adjustable?

Click to expand...

one op-amp (ie 1/2 X LM324) is used for differenciator, when ever there is a change in frequency it will give a voltage output. but what you are interested is NOT in ALL frequency changes. ie: you have a allowable margin. the second op-amp helps you to set your margin, the preset 100K variable will help you to do this.

for the time use two batteries to get 12, 0, -12 V and check your circuit. ie connect both in series and the middle is the ground point. once your circuit works try for the negetive voltage generator to operate it.

if you will face problem in adjusting the range of the frequency input for the circuit, still you can use it with available range, but you need an iput of 0-10kHz range, for that you can use a megnetic pickup from the engine shaft and make it to be excited by many megnets arranged in the circomference of the shaft flange, it is like you are increasing the resolution of the input.

ex: if you use 10 megnets then your frequency out put will be 9000/60 x10 = 1500 Hz.